Rhododendron plant named ‘QBackA’

ABSTRACT

A new and distinct  Rhododendron  cultivar named ‘QBackA’ is disclosed, characterized by distinctive large, fragrant, orange and orange-red flowers. Plants are deciduous, tolerant of heat and humidity, tolerant of mildew and begin blooming before foliage emerges. The new cultivar is a  Rhododendron , suitable for ornamental garden purposes.

Latin name of the genus and species: Rhododendron hybrid.

Variety denomination: ‘QBackA’.

BACKGROUND OF THE INVENTION

The new cultivar is a product of a planned breeding program by theinventor, Robert Edward Lee. The inventor's intention was to developRhododendron hybrid plants with tolerance for heat and humidity andfragrant flowers with vibrant colors. This new variety, hereinafterreferred to as ‘QBACKC’, was discovered as a seedling, resulting fromthe crossing of an unnamed, unpatented, proprietary seedling, resultingfrom the open pollination of Rhododendron austrinum with Rhododendronhybrid ‘George Reynolds, unpatented’ with the pollen parent,Rhododendron hybrid ‘Chectco’, unpatented. The cross was performedduring the Spring of 1984, and the new variety selected by the inventorduring Spring of 1990 in Folsom, La.

After identifying the new variety as a potentially interestingselection, the inventor first propagated ‘QBackB’ by vegetative softwoodcuttings during late Spring of 1990 at a commercial nursery in Folsom,La. The inventor continued confidential and controlled testing andpropagation, assessing stability of the unique characteristics of thisvariety. Multiple generations have been reproduced and have shown thatthe unique features of this cultivar are stable and reproduced true totype.

SUMMARY OF THE INVENTION

The cultivar ‘QBACKA’ has not been observed under all possibleenvironmental conditions. The phenotype may vary somewhat withvariations in environment such as temperature, day length, and lightintensity, without, however, any variance in genotype. The followingtraits have been repeatedly observed and are determined to be the uniquecharacteristics of ‘QBACKA’ These characteristics in combinationdistinguish ‘QBACKA’ as a new and distinct Rhododendron cultivar:

-   -   1. Vibrant Orange and Orange-Red flowers.    -   2. Plant naturally forms a small tree to a large bush form, with        maturity 5 to 6 feet wide and 8 to 10 feet tall, and tolerates        pruning to a smaller size.    -   3. Fragrant flowers    -   4. Manageable growth habit    -   5. Large bloom size    -   6. Large bloom truss    -   7. Blooms open before foliage appears in established landscape        planning    -   8. Heat and humidity tolerant    -   9. Increased tolerance to mildew Erysiphe azaleae

COMPARISON TO PARENT VARIETY

‘QBACKA’ is similar in most horticultural characteristics to the unnamedseed parent variety. Plants of the new cultivar ‘QBackA’ however,produce larger flowers, and begin blooming later than the seed parent.Additionally, plant habit is overall more manageable and better suitedto landscape situation than the seed parent.

‘QBackA’ is similar in most horticultural characteristics to the pollenparent Rhododendron hybrid ‘Chectco’. Plants of the new cultivar‘QBackA’ however, differ in the following characteristics:

-   -   1. More heat tolerant than pollen parent.    -   2. Slightly smaller flower size than pollen parent.    -   3. More mildew resistance than pollen parent.    -   4. Earlier blooming time than pollen parent.    -   5. More manageable and attractive growth habit than the pollen        parent.

COMMERCIAL COMPARISON

‘QBackA’ can be compared to the commercial variety Rhododendron hybrid‘Admiral Semmes’ unpatented. Plants of the new cultivar ‘QBackA’ aresimilar to plants of ‘Admiral Semmes’ in most horticulturalcharacteristics, however, plants of the new cultivar ‘QBACKA’ differ inthe following characteristics:

-   -   1. The new variety has an orange and orange-red flower colored,        compared to the yellow flowers of ‘Admiral Semmes’.    -   2. The new variety begins blooming earlier than ‘Admiral        Semmes’.    -   3. ‘QBackA’ reaches a mature height of 8 to 10 feet, ‘Admiral        Semmes’ reaches a mature height of approximately 4 to 5 feet.

‘QBackA’ can be compared to the commercial variety Rhododendron hybrid‘QBackB’ Plant patent application Ser. No. 14/120,168. Plants of the newcultivar ‘QBackA’ are similar to plants of ‘QBackB’ in mosthorticultural characteristics, however, plants of the new cultivar‘QBackA’ differ in the following characteristics:

-   -   1. ‘QBackA’ has orange and orange-red flowers, whereas ‘QBackB’        has yellow-orange flowers with orange-red flush.    -   2. ‘QBackA’ begins blooming approximately 2 weeks earlier than        ‘QBackB’.    -   3. ‘QBackA’ reaches a mature height of 8 to 10 feet, ‘QBackA’        reaches a mature height of approximately 6 to 8 feet.

BRIEF DESCRIPTION OF THE PHOTOGRAPH

The accompanying photograph in FIG. 1 illustrates in full color atypical plant of ‘QBackA’, of approximately 2 years old.

FIG. 2 illustrates a close up of typical flowers of the new variety.

The photographs were taken using conventional techniques and althoughcolors may appear different from actual colors due to light reflectanceit is as accurate as possible by conventional photographic techniques.

DETAILED BOTANICAL DESCRIPTION

In the following description, color references are made to The RoyalHorticultural Society Colour Chart 2007 except where general terms ofordinary dictionary significance are used. The following observationsand measurements describe ‘QBACKA’ plants grown outdoors in Loxley, Ala.Plants are approximately 2 years old, in a 3 gallon nursery container.Measurements and numerical values represent averages of typical planttypes.

-   Botanical classification: Rhododendron hybrid ‘QBACKA’.

PROPAGATION

-   Typically by semi-hardwood cuttings in spring and summer.-   Time (approximate days) to initiate roots: 30 to 60 days at 70 to 80    degrees F. day temperatures and 55 to 65 degrees F. night    temperatures.-   Time (approximate days) to produce a rooted plant: Approximately    150-210 days at 70 to 80 degrees F. day temperatures and 55 to 65    degrees F. night temperatures.-   Root description: Fine, fibrous young roots, well branched. Colored    near RHS Grey-Brown 199A.

PLANT

-   Growth habit: Upright, deciduous woody shrub.-   Height: Approximately 22 cm to top of foliar and flowering plane.-   Plant spread: Approximately 30 cm.-   Branching characteristics: Average 2 primary branches from the    center of the plant, after pinching. Branches occur at approximately    15° to 35° angles. Each primary branch has an average of 4 lateral    branches.-   Primary branches:    -   -   Length of primary branches.—Average 22 cm, then splits into            lateral branches.        -   Diameter of primary branches.—Approximately 1.2 cm.        -   Primary branch strength.—Very strong, difficult to break.        -   Primary branch color.—Near RHS Grey-Brown 199B.        -   Primary branch texture.—Young growth pubescent to nearly            hirsute. Hairs, approximately 0.15 cm long, colored near            Yellow-Green 145C. Older growth moderately scaly,            non-pubesscent.-   Lateral branches:    -   -   Number of lateral branches.—Average 4 per primary branch.        -   Length of lateral branches.—Average 10 cm, then splits into            more branches.        -   Diameter of lateral branches.—Average 0.4 cm.        -   Lateral branch strength.—Very strong, not flexible,            difficult to break.        -   Lateral branch color.—Near RHS Greyed-Green 197B.        -   Lateral branch texture.—Scaly.-   Internode length: Average 10 cm.-   Age of plant described: Approximately 2 years.

FOLIAGE

-   Leaf:    -   -   Type.—Simple.        -   Arrangement.—Leaves occur in a whorl at the end of branches.        -   Average length.—Approximately 6.4 cm.        -   Average width.—Approximately 2.3 cm.        -   Shape of blade.—Elliptic.        -   Apex.—Acute to slightly Mucronate.        -   Base.—Attenuate.        -   Attachment.—Sessile.        -   Margin.—Entire.        -   Texture of top surface.—Pubescent. Hairs appressed, minute,            and slightly to moderately dense.        -   Texture of bottom surface.—Pubescent. More hairs present            along main vein and margin.        -   Appearance of top surface.—Matte, not glossy.        -   Appearance of bottom surface.—Matte, not glossy.        -   Color.—Young foliage upper side: Near RHS Yellow-Green 144A,            flushed Greyed-Purple 183B. Young foliage under side: Near            RHS Yellow-Green 144A. Mature foliage upper side: Near RHS            Yellow-Green 144A, faintly flushed Greyed-Purple 183B.            Mature foliage under side: Near RHS Yellow-Green 144A.-   Venation:    -   -   Type.—Pinnate. Underside of leaf veins prominently raised.        -   Venation color upper side.—Near RHS Yellow-Green 153D.        -   Venation color under side.—Near RHS Yellow-Green 153B.

FLOWER

-   Bloom period: Plants begin flowering mid April, and are not known to    flower again in the same year.-   Flower:    -   -   Arrangement.—Axillary clusters of single, perfect, open            funnel shaped individual flowers. Typically 5 to 8 open            flowers and 5 buds per cluster.-   Inflorescence:    -   -   Height.—Average 11.0 cm.        -   Diameter.—Average 12.0 cm.        -   Overall shape.—Flattened globular.-   Peduncle: No true peduncle, flower cluster emerges directly from    lateral woody stem.-   Pedicel:    -   -   Length.—Average 1.0 cm.        -   Diameter.—0.25 cm.        -   Color.—Near RHS Yellow-Green 144B, slightly flushed with            Greyed-Orange 173A and 173B near flower attachment.        -   Texture.—Densely pubescent.        -   Aspect.—Straight. Angle of attachment, approximately 75°            angle from stem, outermost flowers.        -   Strength.—Strong and flexible.-   Flowers:    -   -   Length.—Average 6.5 cm.        -   Diameter.—Average 6.0 cm.        -   Facing direction.—Outwardly and upwardly facing.        -   Persistent or self-cleaning.—Petals self-cleaning.        -   Fragrance.—Very faint, sweet fragrance.        -   Tube.—Tube length: Approximately 2.5 cm. Tube width a widest            point: Approximately 1.4 cm. Tube width and narrowest point:            Approximately 0.6 cm. Color: Inner surface at first opening:            Near RHS Orange 24A. Outer surface at first opening: Near            RHS Orange-Red 32B, streaked Orange-Red N30B. Inner surface            at maturity: Near RHS Orange 28C. Outer surface at maturity:            Near RHS Orange-Red 34A. Inner surface at fading: Near RHS            Orange 28C. Outer surface at fading: Near RHS Orange-Red.        -   Petals.—Unfused petal segments: Length: Approximately            3.0 cm. Width: Approximately 2.0 cm. Apex: Ruffled. Shape of            petal: Unfused portion, obovate. Petal margin: Ruffled.            Petal Arrangement: Approximately ⅓ fused from base. Unfused            section overlapping. Petal Number: 5. Petal Texture: Smooth,            all surfaces. Color: Inner surface at first opening: Near            RHS Orange 24A, streaked Orange-Red 32B. Outer surface at            first opening: Near RHS Orange-Red 34A and 34B, streaked            Yellow-Orange 15C. Inner surface at maturity: Near RHS            Orange-Red N34A, Yellow-Orange 20A, Orange-Red 34C, Orange            N25B. Colors present individually, in irregular streaks.            Outer surface at maturity: Near RHS Orange-Red 34A, with            streaks of Yellow-Orange 20A. Inner surface at fading: Near            RHS Orange 25B, flushed with Orange-Red 34A. Outer surface            at fading: Near RHS Orange-Red 34A, streaked Orange 24B.-   Bud:    -   -   Shape.—Elliptic, with inflated apical end.        -   Length.—2.8 cm.        -   Diameter.—1.4 cm at widest point.        -   Color.—Near RHS Orange-Red 34B.-   Calyx/sepals:    -   -   Quantity per flower.—5 sepals.        -   Shape.—Deltate.        -   Length.—0.4 cm.        -   Width.—0.3 cm.        -   Apex.—Acute.        -   Base.—Fused.        -   Margin.—Entire.        -   Texture.—Highly pubescent inner and outer surfaces.        -   Color.—Inner Surface: Near RHS Green 138A. Outer Surface:            Near RHS Green 137D.

REPRODUCTIVE ORGANS

-   Stamens:    -   -   Number.—5.        -   Length.—6.1 cm.        -   Width.—0.15 cm.        -   Color.—Near RHS Greyed-Red 80A, upper ⅕ near Green-Yellow            1A.        -   Anthers.—Length: Approximately 0.4 cm. Width: Approximately            0.2 cm. Shape: Linear. Color: Near RHS Yellow 7D. Pollen:            Scant, colored near Greyed-Orange 164D.-   Pistil:    -   -   Number.—1.        -   Length.—6.6 cm.        -   Style.—Length: 6.4 cm. Color: Near RHS Orange-Red 34B.        -   Stigma.—Globular, colored near Yellow-Green 147A.        -   Ovary.—Sericeous texture. Approximately 0.2 cm in diameter.            Colored near Yellow-Green 147A.

OTHER CHARACTERISTICS

-   Disease and pest resistance: Not observed to be susceptible nor    resistant to normal pests of Rhododendron hybrid. Increased    tolerance to mildew Erysiphe azalea.-   Temperature tolerance: USDA Zone 6.-   Fruit/seed production: Not observed to date.

What is claimed is:
 1. A new and distinct cultivar of Rhododendron plantnamed ‘QBACKA’ as herein illustrated and described.